Island



(No Model.) a Sheets-Sheet 1.

J. W. SARGENT,

VALVE GEAR.

No. 516,634. Patented Mar. 13, 1894.

INNER)! Wake-mm (No Model.) 3 Sheets-Sheet 2. J. W. SARGENT.

VALVE GEAR.

lip. 51634. Patented Mar. 13, 1894.

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(No Model.) I 3 Sheets-Sheet 3.

J. W. SAIRGENT.

VALVE "GEAR.

' No. 516,634. PatentedMar. 13, 1894.

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UNITED STATES ATENT FFICE.

JOHN IV. SARGENT, OF PROVIDENCE, RHODE ISLAND.

VALVE-G EAR.

SPECIFICATION forming part of Letters Patent No. 516,634, dated March13, 1894.

Application fil d October 2,1893. Serial No. 487,010. (No model.)

To all whom it may concern.-

Be it known that I, JOHN W. SARGENT, a

citizen of the United States, residing at Providence, in the State ofRhode Island, have invented a new and useful Improvement in Valve-Gearsfor Steam-Engines, of which the following is a specification. The objectof my invention is to provide improved means for operating the inletvalves of a steam engine, whereby the steam will be out offautomatically by the action of a governor, and my invention consists inthe improved construction and arrangement of the several parts; thedevice, as shown in the drawings, being applied to an engine of theGreene type, in which the inlet valves are flat gridiron slide valves.

Referring to the drawings: Figure 1, represents a side elevation of anengine cylinder provided with my improvement, for operating the valves.Fig. 2, represents a partial end elevation of the same. Fig. 3,represents an enlarged side elevation of the valve gear separate fromthecylinder. Fig. 4, represents a horizontal section taken in theline t, 4,of Fig. 3. Fig. 5, represents an enlarged end elevation of the valvegear. Fig. 6, represents a side View of the trip collar, which isoperated by the governor, for controlling the closing movement of thevalve. Fig. 7, represents a vertical section taken in the line 7, 7, ofFig. 3. Fig. 8, represents a top View of the engine cylinder and thevalve gear.

In the accompanying drawings, A represents the cylinder of the engine,and B and B the steam chests, containing fiat gridiron valves, havingvalve stems O, G, projecting through suitable stuffing boxes, andconnected by means of the pins D, D, with the lower ends of the rockerarms E, E, which latter are at their upper ends keyed to the rockshaftsF, F, respectively. The rock-shafts F, F, are carried at their innerends by bearings in the pedestal G, and at their outer ends in thepedestal H, the said rock shafts being arranged horizontally, andparallel with each other, and at a comparatively short distance apart.The outer pedestal H,is supported by means of a table I, which is firmlybolted to the cylinder A, and to the outer end of each rock shaft iskeyed a driving arm as J, J, which when in its middle position hangs atabout an angle of forty five degrees with a vertical line. The pedestalH is provided with the outwardly extending hubs or bushings, L, L, uponwhich are loosely held the rockers N, N, and the lower end of eachrocker N, N, is provided with an outwardly extending boss 0, and a pinP, and each of the pins P, P, of the rockers is held in one of the boxesQ,Q, carried in the forward end of the link It, connected with theeccentric. The centers of the boxes Q, Q, and of the pins P, P, of therockers, are arranged at the same horizontal distance apart as thecenters of the rock shafts F, F, thus forming a parallel movement forthe forward end of the link R. In front of the rockers N, N, andprejecting upward and outward from the boss 0 are lugs S, S, forengaging with the toes t, t, of the latches T, T, which are pivoted tothe Studs U, U, extending inwardly from bosses at the outer ends of thedrivingv arms J, J. The latches T, T, are provided with long hubsextending inwardly upon the studs U, U, and with the upwardly extendingtrip arms '0, t, which engage with the studs W, W, for liberating thecut-off. The studs W, W, are held by the arms X, X, of the tripcollarsY, Y, which latter are loosely fitted to the stationary hubs or bushingsL L, and are free to turn upon the same when actuated by the governor.The trip collars Y, Y, are geared together by the teeth a, so as tocause them to move simultaneously, and rotate in opposite directions,thus causing the trip studs W, W, to rise and fall together.

The trip collar Y isprovided with an arm A, extending upward, the saidarm being connected with the governor by means of the link G.

The rotation of the main shaft of the engine, will impart by means ofthe eccentric and the link R, a continuous rocking movement to both ofthe rockers N, N, and as shown in Figs. 1 and 3, the backward movementof the link R, will cause the lug S of the rocker N, to engage with thetoe t of the latch T, of the driving arm J, so that the said driving armwill at first be moved along with the rocker N, thereby turning therockshaft F, which by its connection with the valve stem 0, will causethe opening of the valve to admit steam to the rear end of the cylinderA. During the opening movement of the valve, and at a point dependingupon the position of the stud W, which is controlled by the action ofthe governor, the stud WV will be engaged by the trip arm 0 of the latchT, and as the end of the arm 1;, moves over the stud, the latch T willbe turned upon its pivot stud U, thus raising the toe t, sufficiently,to cause the disengagement of the same from the lug S; the valve willthen he suddenly closed by the steam pressure on the valve stem,and theweighted dash-pot (not shown in the drawings), which is connected to therock shaft F, by means of the Weight rod H, and the weight rocker Twhich is keyed to the rock shaft. The dashpot cushions and limits theclosing movement of the valve, and the connected parts.

In Fig. 3, the forward driving arm J and toe t are shown at the extremeclosed condition of the valve at the forward end of the cylinder; andthe extreme backward position of the lug S, of the rocker N, is shown bythe dotted line 0, the toe if, having in the meantime been raised by theinclined back of the lug, and then dropped in front of the same,likearatchet pawl. The forward movement of the link R, will cause theengagement of the lug S and toe thus causing the movement of the drivingarm J and rockshaft F to open the forward valve of the cylinder, untilthe trip arm '0 of the latch T, strikes the stud U of the trip collar Y,and allows the valve to close in the same manner as the valve at therear end of the cylinder, before described. Each of the driving toes z,t, is limited in its downward movement, by

means of the lugs cl, projecting from the inner sides of the drivingarms J, J, and the lugs e which are raised up from the hubs of thelatches T, T.

I claim as my invention- 1. In an automatic cut-oft valve gear, thecombination with the link actuated by the eccentric, and provided withthe duplicate boxes, the rock-shafts provided with the driving arms, andthe swinging rockers arranged to form a parallel movement with the linkand the rock-shafts, of the driving lugs upon the rockers, the latchesprovided with the trip arms and pivoted to the driving arms forengagement with the lugs of the rockers, and the independently held tripcollars, geared to each other, and connected with the governor,substantially as described.

2. In an automatic cut-off valve gear, the combination with the pedestalprovided with the outwardly projecting hubs, the rock shafts passingthrough the said hubs and provided with the driving arms, the linkprovided with the boxes arranged at a distance from each othercorresponding with that of the rock shafts, the rockers held upon thehubs of the pedestal and provided with the driving lugs, the latchesprovided with the trip arms and pivoted to the driving arms, and thegeared trip-collars arranged upon the hubs of the pedestal, andconnected with the governor, substantially as described.

JOHN W. SARGEN'I.

Witnesses:

WM. B. WATERMAN, S. SCHOLFIELD.

